Dogs are smarter than cats, study finds

— -- Dog owners now have scientific data to back them in the eternal debate over whether dogs really are smarter than cats.

A study led by a Vanderbilt University professor counted for the first time the number of cortical neurons in the brains of cats and dogs and found that dogs possess nearly double the amount of neurons compared to cats.

Researchers at Vanderbilt University found that dogs have 530 million neurons in their cerebral cortex, while cats have only half that amount, or around 250 million.

“Neurons are the information-processing units in the brain, and the cerebral cortex is the part of the brain that can combine information from different sources and create new associations, recognize patterns, make decisions to act differently based on past experience and start making predictions for the future," Suzana Herculano-Houzel, the Vanderbilt professor who developed the method for measuring neurons, told ABC News.

"Whatever species has the most neurons in the cerebral cortex is therefore expected to be capable of more complex and flexible behavior, said Herculano-Houzel, who gave the disclaimer she is "100 percent a dog person." "We humans have twice the cortical neurons that gorillas have; dogs, as we found out, have about twice the cortical neurons that cats have."

The number of neurons in an animal also determines the “richness of their internal mental state and their ability to predict what is about to happen … based on past experience,” researchers said.

Herculano-Houzel studied the number of neurons in the brains of animals including a ferret, mongoose, raccoon, lion and more. The research was accepted this week for publication in the journal Frontiers in Neuroanatomy.

Researchers also found that the brain of a golden retriever has more neurons than the striped hyena, African lion and brown bear, even though a brown bear has a cortex up to three times larger than a dog.